Contact body

ABSTRACT

A contact body for contacting traveling materials treated with lubricating substance, such body comprising a thermally conductive base member having a surface adjacent to the path of travel of the materials and consisting of a first material subject to attack by the lubricating substance, and a coating applied to the surface and consisting at least in part of a second material which is impermeable to the lubricating substance and which is not subject to attack by the same.

United States Patent UNITED STATES PATENTS Weinberg ..29/199 Lee 51 May 2, 1972 [541 CONTACT BODY 2,891,303 6/1959 Stevenson ..29/1s3 3,249,409 5/1966. McLeod ...29/196.3 [72] England 3,249,478 5/1966 Brevik ..29/196.3 [73] Assignee: Ernest Scragg & Sons Limited, Mac- 3,480,411 1 1/ 1969 Pryor ..29/ 183 clesfield, Cheshire, England [22 1 Filed, 11 1969 Primary Examiner-Byland Bizot Attorney-Michael s. Striker [21] Appl. No.: 884,387

Related US. Application Data [57] ABSTRACT 63] Continuation of Ser. No. 625,910 Mar- 22 1967 A contact body for contacting traveling materials treated with lubricating substance, such body comprising a thermally conabandoned.

ductive base member having a surface ad acent to the path of 30] Foreign Application Priority Dam travel of the materials and consisting of a first material subject to attack by the lubricating substance, and a coating applied to Mar. 22. 1966 Great Britain ..44,805/66 the surface and consisting least in pan f a Second material which is impermeable to the lubricating substance and which [52] US. Cl ..29/191.6, 28/62, 29/199 is not Subject to attack by the same [51] Int. Cl. ..D02 13/00 [58] Field 0fSearch.... ....29/196.3,191, 183, 199, 191.6; 28/62 [56] References Cited 6 Claims, 4 Drawing Figures PATENTED MY 2 I973 2/ 25 2; FIG-4 INVENTOR AROLP L/ILLJAM LEE 3/: ATTOiNEY CONTACT BODY CROSS-REFERENCE TO RELATED APPLICATION This is a continuation of my application Ser. No. 625,910 filed Mar. 22, 1967, now abandoned.

BACKGROUND OF THE INVENTION The present invention relates to the processing of filamentary materials in general, and more particularly to the heat treatment of filamentary materials. Still more particularly, the present invention relates to contact heaters for filamentary materials, and specifically to contact members for such heaters which contact traveling filamentary materials for treating the same.

Filamentary materials, and particularly man-made fibers, are frequently subjected to a heat treatment for various reasons well known in the art. To this end, they are conventionally passed over a yarn contact member which is adapted to be heated in some fashion, and by contact with the surface of such member heat is imparted to the filamentary materials which, it should be understood, travel as they contact the surface of such contact members. Usually, these members are maintained in operation at a temperature of approximately 250 C.

It is known to construct such members from a base or support consisting of light-gage sheet copper, and a hard chromium plating which is adhered to the copper and over a free surface of which the yarn moves in engagement therewith. To reduce friction of the yarn, that is to lubricate it, the yarn is treated with a so-called spin finish, usually a textile oil whose fatty acid content may vary according to its source and in dependence upon various other factors which are of no concern in the context of the present invention.

What is, however, of concern is the face that the chromium is porous and permits this oil to penetrate by capillary action to the interface between the chromium and the copper where corrosion may occur as a result of direct chemical attack by constituents of the oil on the copper. Usually the fatty acids in the oil will be of sufficient strength to cause such corrosion if they can reach the copper. This results in the formation of corrosion cells between the copper, chromium, and textile oil which acts as an electrolyte whereas the copper acts anodically on the chromium. This corrosion attack is assisted by the relatively high operating temperature of the yarn contact member which, as mentioned above, is maintained at a temperature of approximately 250 C. It is this corrosion attack which, it is thought, is responsible for the progressive removal of the chromium plating which is sometimes observed on the yarn contact members of this type. Of course, the extent of the attack varies according to the textile oil which is employed to impart to the yarn the spin finish, that is according to the constituent components of the textile oil, including the fatty acids. In any case, however, the mechanism by which the chromium plating is removed seems to involve a cumulative attack on either side of the corrosion pit and the interface of chromium and copper. If the pores in the chromium become blocked by corrosion products, gas pressure develops at this interface and assists in further removing the chromium plating from the copper.

This problem is made still more difficult by the fact that the yarn contact members of this type are not maintained at the elevated temperature at all times. It is necessary to cool these members periodically for various reasons, for instance to clean reaction products from the contact surface over which the filamentary materials pass. This thermal cycling is highly disadvantageous and assists in the destruction of the chromium plating because it promotes the appearance of fissures in the chromium, resulting from the different linear thermal expansion characteristics of copper on the one hand and chromium on the other hand. Evidently, the appearance of such fissures facilitates the passage of the textile oil to the interface, which can now take place more rapidly than if it were to depend on capillary action alone, and this is likely to accelerate thecorrosion attack.

SUMMARY OF THE INVENTION The present invention overcomes these disadvantages known art.

More particularly, the present invention provides a yarn contact member, such as a yarn contact plate, wherein the possibility of attack of the copper base by the constituent components of the spin finish oil is removed.

Also, the present invention provides such a yam contact member wherein the development of fissures in the coating applied to the base in response to thermal cycling of the member is reduced or completely eliminated.

A yarn contact member in accordance with the present invention is simple to construct and therefore inexpensive, and it has operating properties and a wear resistance which'are at least equal to those of yarn contact members of conventional type as set forth above.

In accordance with one feature of my invention, I provide a contact plate for contacting traveling materials, and particularly for contacting textile filaments which are treated with a lubricating substance. This contact plate comprises a thermally conductive base member the surface of which is adjacent to the path of travel of the materials, and this base member consists of first material, usually copper, which is subject to attack by the lubricating substance of the traveling materials. A coating is applied to the surface of the base member and this coating consists in part at least of a second material which is impermeable to the lubricating substance and which is not subject to attack by the same.

In accordance with the invention, this coating applied to the surface of the base member may consist of two strata or layers, one of which is directly adhered to the surface of the base member and consists of the aforementioned second material, whereas the other is adhered to the one layer and consists of chromium or a similar material.

In accordance with a further feature of the invention at least the one layer may advantageously have a linear thermal expansion characteristic which is intermediate the similar expansion characteristics of the aforementioned other layer and the base member. The one layer, that is the layer consisting of a second material as pointed out earlier, may be a layer of nickel or of an alloy comprising nickel as its main constituent.

The invention provides also that if the coating consists of at least two layers of different materials, the materials of these two layers should be so selected that substantially no electrolytic corrosion cells can form at the interface of these layers in the presence of textile oil as an electrolyte.

of the The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a top-plan view of a yarn contact member in accordance with the present invention;

FIG. 2 is a section taken on the line AA of FIG. 1, showing a somewhat schematic cross section of one embodiment of the invention;

FIG. 3 is a view similar to that of FIG. 2, showing a second embodiment of the invention; and

FIG. 4 is a view similar to FIGS. 2 and 3, but showing a third embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing in detail, and firstly FIGS. 1 and 2 thereof, it will be seen that the yarn contact heating member or element is indicated with reference numeral 11. It will be understood that this contact member is part of a yarn heater whose construction is well known in the art and which is therefore not believed in need of description.

The yarn contact member in the illustrated embodiment is in the form of an elongated strip and provided with a yarn con-1 usually several channels 29 (see FIG. 2) in which the yarn or filament to be treated can travel to the guided thereby (see FIG. 1). A plurality of lugs 31 are provided by means of which the contact member 11 can be secured to a support or base, which maybe a part of a textile machine or the like. I

As the illustration in FIG. 2 shows'clearly, the yarn contact member 11 is provided with a metallic support member 15, usually consisting of light-gage sheet copper. A free surface of the member is provided with a coating in form of a layer 17, of a non-porous material which is not liable to chemical attack by a lubricant, such as a textile oil carried by the yarn which,

in operation, contacts the contact surface 13 of the member 1 1.

As is illustrated in FIG. 2, the layer 17 may be directly adinch is preferred. Advantageously, the backing or support member 15 may be curved in the direction of yarn travel. The thickness of the layer 17, that is in the preferred embodiment of the plating of nickel or nickel-alloy, should be uniform and preferably on the order of 0.001 inch. Various methods for depositing such a coating are of course known, but it has been found that a highly satisfactory nickel plating of very uniform thickness may be produced by the Kanigen process (Trade Mark) which involves the deposition of nickel from a nickel i dispersion in the bath, rather than using electrodes. The resulting layer is a coating of nickel phosphorus.

The coating of nickel or of a nickel alloy is not permeable to the textile oil since it does not have capillary passages such as are found in a chromium coating. Furthermore, nickel or nickel alloys are'not subject to attack by the oils used in the treatment of filamentary materials.

In the embodiment of FIG. 2, it is of course the free surface of the layer 17 which constitutes the contact surface'l3 of contact member 11.

FIG. 3 shows another embodiment of the invention accord ing to which the layer 17 is adhered not directly to the surface of the support member 15, but is separated from the latter by an interposed intermediate layer 19, to whose free surface the layer 17 is in turn adhered. With a construction such as shown in FIG. 3, the layer 19 is advantageously so selected that it has a linear thermal expansion characteristic intermediate the expansion characteristics of the support member 15 and the layer 17 to reduce or at least substantially eliminate the possibility that cracks or fissures form in the layer 17 during the thermal cycling which the member 1 1 must inevitably undergo during operation as a contact heater member. In the embodiment of FIG. 3, just as in the embodiment of FIG. 2, it is the free surface of the layer 17 which serves as the contact surface 13 over which the yarn moves in direct engagement therewith.

In the embodiment .of FIG. 4 which again is different ad hered from those of FIGS. 2 and 3, the layer 17 is adhered directly to a surface of the support member 15, as in the embodiment of FIG. 2. Unlike the embodiment of FIGS. 2 and 3, however, the contact surface 13 is not constituted by a free surface of the layer 17. Rather, in the embodiment of FIG. 4, the layer 17 is interposed between the support member 15 and an additional layer 25 which is deposited on the layer 17 and a free surface 23 of which constitutes the contact surface 13 shown in FIG. l. The additional layer 25 is a layer of porous material as opposed to the material of layer 17, and such porous material ma for instance by a hard, as distinct from a right, chrorruum p atlng. Of course, the material of the additional layer 25 must not be subject to attack by the textile oil, any more than the material of layer 17 is subject to such attack. It will furthermore be evident that the materials of layers 17 and 25 should be so selected that no electrolytic corrosion cells are formed at the interface of these layers in the presence of textile oils which can act as an electrolyte. It will also be understood that the nomporous layer 17 shown in FIG. 4 may naturally be adhered to layer comparable to the layer 19 in FIG. 3, that is an additional layer interposed between the ayer l7 and the support member 15. i

The non-porous layer 17 may, but need not necessarily, have a linear thermal expansion characteristic intermediate the similar characteristics of the porous layer 25 and the support member 15 in the construction shown in FIG. 4.

Evidently, a contact member such as the member I 1 shown in FIG. 1 must be heated by a suitable heating means to perform its intended function, but this construction is so conventional that there is believed to be no need for indicating a heating means. This will be quite readily understandable to persons skilled in the art.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of arrangements differing from the types described above.

While the invention has been illustrated and described as embodied in a contact body, it is not intended to be limitedto the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can be applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior rt, fairly constitute essential characteristics of the generic or 'speciric aspects of this invention and, therefore, such adapta- *tions should and are intended to be comprehended within the :tneaning and range of equivalence of the following claims.

4 What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

I claim:

1. A contact heater plate for processing travelling yarn which carries a spin-finish substance comprising a heating element of good thermal conductivity and composed of a metallic material subject to attack by said spin-finish substance upon contact therewith; at least one path-defining recess at a surface of said heating element for passage of the travelling yarn; a layer of chromium on said surface; and a non-porous layer of a metallic material not subject to attack by said sub stance between said layer of chromium and said surface and having a coefficient of thermal expansion intermediate the coefficients of thermal expansion of said chromium layer and said heating element.

2. A contact heater plate as defined in claim 1, wherein said heating element consists of copper.

3. A contact heater plate as defined in claim 1, wherein said heating element consists of sheet copper having a thickness in the range between three-sixteenths andbne-fourth of an inch.

4. A contact heater plate as defined in claim 1, wherein said' 

2. A contact heater plate as defined in claim 1, wherein said heating element consists of copper.
 3. A contact heater plate as defined in claim 1, wherein said heating element consists of sheet copper having a thickness in the range between three-sixteenths and one-fourth of an inch.
 4. A contact heater plate as defined in claim 1, wherein said non-porous layer consists of nickel.
 5. A contact heater plate as defined in claim 1, wherein said non-porous layer consists of an alloy containing nickel as its predominant constituent component.
 6. A contact heater plate as defined in claim 1, wherein said heating element is elongated and of strip-shaped configuration. 